<template>
  <div>
 
    <input
      :class="{
        checked,
      }"
      v-model="checked"
      type="checkbox"
      id="a"
    />
    <label
      :class="{
        checked,
      }"
      for="a"
    > 备选框</label
    >
  </div>
</template>

<script>
export default {
  data() {
    return {
      checked: false,
    };
  },
};
</script>

<style>
input.checked {
 outline: 1px solid blue;
}
label.checked {
 color: blue;
}
</style>
